The Wall Street Journal has published two articles about enterprise wikis, both of which mention Atlassian customers and their use of wikis for collaboration and knowledge management:
Mr. Yolton’s group put the most relevant questions and answers on a wiki and started encouraging people in the so-called SAP community — employees, software developers, customers and so on — to contribute. Mr. Yolton uses software called Confluence from Atlassian Software Systems Pty. Ltd. of Sydney, Australia.
You can read each article here: